11011 12mm Backplate and Starter Rod. Includes 11012 14mm Backplate. Will fit a few 1/10 models - Please check measurements below. To suit .12 to .18 engines only. Not suitable for engines larger than .18 (.19 etc). Not suitable for 1/16 engines (.07 or .05 for example). To check if this will fit your model please remove the pull starter and check the measurements: - Across the center of fixing holes top right to top left - Across the flats of hex shape in middle of backplate. Distance between center of fixed holes across top right top left is 27mm (same for all sides) and 32mm for the 4 hole backplate. Hex gear size is to fit a 12mm one way bearing (B on diagram). Hex gear size is to fit a 14mm one way bearing (B on diagram). Note: one way bearing not included. Note: gear size can be swapped with the other backplate included. Other sizes available please ask or see our other listings. Please contact us if your unsure. Note: This item will not fit Thunder Tiger models. Note: Drill etc (parts not pictured) are not included.